What does Macbeth's 'Is this a dagger which I see before me' soliloquy show about his character?and what is the significance of this moment in the...

When Macbeth sees the bloody dagger, he is moments away
from killing King Duncan. Obviously, Macbeth is feeling the guilt of murderous actions
he has not yet committed. Macbeth is preparing to kill King Duncan. He is preparing to
murder him as he sleeps. The dagger he sees is some type of omen that the witches desire
him to follow. The dagger leads to where Duncan is sleeping. Macbeth speaks to the
dagger:

You
guide me on the way that I was going,
And show me the instrument I was to
use.

In a few moments,
Macbeth will actually hold a bloody dagger as he murders King
Duncan.

Macbeth is already feeling the effects of the
murder. He is having hallucinations about the terrible act he is about to do. His guilt
is overtaking his reasoning. The dagger represents the bloody course on which Macbeth is
about to undertake.